If you're new to boating, you may have invested a pretty penny in your new vessel and all the various support tools. You will always have one eye on your expenses and will want to ensure that your equipment lasts as long as possible. As a consequence, you will want to look after all those metal components that sit underneath the water to make sure that they don't rust away to nothing. Welcome to the world of sacrificial anodes. What are these and why are they very important?
Dealing with Corrosion
Whether you will pursue your hobby in saltwater or freshwater, you need to be worried about corrosion. Unless you take specific actions, this will eat away at the metals beneath the waterline, including the hull itself, the prop shaft, sterndrive and so on. This, of course, is not good and will result in replacements and repairs before you know it. In order to avoid this situation, you need to feed the corrosion some electrons instead. These electrons are contained within the sacrificial anodes and will essentially attract the corrosion to this point.
How Do Anodes Work?
Anodes can come in a variety of different materials, including zinc, magnesium and aluminium. These different materials will perform best depending on the type of metal you're going to protect and the nature of the water within which you are immersing. The anode has a specific type of voltage, with the higher the amount the more electrons available and the more protection given.
Without getting too technical, remember that the anode is setting up a variation in electrical current in order to attract the corrosion. Some materials are able to create higher electrical potential than others and as such can provide you with more protection for a longer time.
The Decision-Making Process
Choose the right type of anode for your boat by figuring out what type of metal you need to protect and where you're going to be sailing. Don't make the mistake of choosing a zinc anode exclusively because people may have told you that it lasts forever. If it does indeed last forever, that means that it is not doing its job as it should be wearing away all the time to protect the other metals.
What's the Best Choice?
If you are planning to take your boat into fresh water situations that tend to be clean, rather than polluted, you should choose magnesium or aluminium anodes across the board. If you will be dipping into polluted water more often, you should probably select aluminium.
Working It out
This entire subject can be a little difficult to comprehend. If you're still unsure, have a word with your equipment supplier, who will be able to give you some guidance in your specific situation.